It is narrated from Abu Qilabah (may Allah have mercy on him): A man came to Sayyiduna Abu Bakr (may Allah be pleased with him) and said, "I saw in a dream that I was urinating blood." He interpreted it: "You have intercourse with your wife during her menstrual period." The man said, "Yes, that is true." He said, "Fear Allah, and do not do this again."